Against a background of an international situation aiming for a low carbon society, the automobile industry, in order to respond to emission regulations that become stricter by the year, is proceeding with a shift from heretofore known vehicles that run by driving an internal combustion engine using a fuel such as gasoline to HEVs or EVs that can run by driving a motor using electrical energy.
As an HEV or EV is such that a large capacity battery is mounted, and the HEV or EV runs by a motor being driven using the power of the battery, a vehicle-mounted charger that charges the battery and a power train for driving the motor using the power of the battery are included.
FIG. 11 shows a configuration example of a heretofore known vehicle-mounted charger and power train used in an HEV or EV.
In FIG. 11, a vehicle-mounted charger 4 includes a power factor control circuit (hereafter referred to as a PFC circuit) 41, a DC/AC converter 42, a transformer 43, a rectifier circuit 44, and a reactor 45, wherein an isolated AC/DC converter is configured of the DC/AC converter 42, transformer 43, rectifier circuit 44, and reactor 45. Also, a power train 5 is configured of a 3-phase inverter 51.
1 is an alternating current power supply, 2 is a battery, and 3 is a 3-phase alternating current motor.
To give a simple description of an operation of FIG. 11, the external alternating current power supply 1 is connected to the vehicle-mounted charger 4 when charging the battery 2. While the power factor of the input current is controlled by the PFC circuit 41 in this condition, the battery 2 is charged by the charging current, power, and voltage of the battery 2 being controlled by the circuit from the DC/AC converter 42 onward. Meanwhile, when the vehicle is running, direct current power of the battery 2 is converted into alternating current power by the inverter circuit 51, thus driving the alternating current motor 3.
The heretofore known technology of FIG. 11 is such that the power conversion circuit configuring the vehicle-mounted charger 4 and the power conversion circuit configuring the power train 5 are provided separately, because of which the circuits have a large number of parts, causing an increase in size and increase in cost of the overall device.
Because of this, heretofore known technology that achieves a reduction in size and a reduction in cost by a power conversion circuit being shared is disclosed in, for example, PTL 1.
FIG. 12 is a circuit diagram of heretofore known technology described in PTL 1. In FIG. 12, components having the same functions as components shown in FIG. 11 are given the same reference signs. In FIG. 12, 6 is a capacitor connected in parallel with the battery 2, 7 is a transformer to a primary side of which an alternating current input is applied, 8 is a filter connected to a secondary side of the transformer 7, and 9 is a cutoff connector provided on the input side of the alternating current motor 3.
The circuit of FIG. 12 is such that, with the cutoff connector 9 in a disconnected condition, an alternating current input is applied to the inverter 51 via the transformer 7 and filter 8, and the battery 2 is charged by an AC/DC conversion operation of the inverter 51. Also, when driving the alternating current motor 3, direct current power of the battery 2 is converted into alternating current power by the inverter 51 with the cutoff connector 9 in a connected condition, and the alternating current power is supplied to the alternating current motor 3.
This heretofore known technology is such that, by the motor driving inverter 51 also being utilized as a charger of the battery 2, the circuit configuration is simplified, and a reduction in size and reduction in cost of the overall device are achieved.